books = ['sanzijing','dizigui','qianziwen','baijiaxing','yibenshu']
#统计书籍总数
print(len(books))
#新增书籍
book = input('要增加的书名：')
books.append(book)
print(books)
# 删除书籍

del_book = input('输入要删除的书：')
if del_book in books:
    del books[books.index(del_book)]
    print('删除后书籍列表：',books)
else :
    print('该书不存在。')

# 书籍列表按字母排序
books.sort()
print(books)
